Are You Getting Enough Vitamin D?

Doctors have long struggled to understand why some women develop gestational diabetes and others don't. Extra weight plays a role, but many slim, otherwise healthy women find their blood glucose inching higher during pregnancy. What else could be going on?

First, there may be an unexpected nutritional link, says a paper published in the American Journal of Obstetrics & Gynecology. Korean researchers measured blood levels of vitamin D in a small sample of 60 women—20 with gestational diabetes and 40 without. The findings? Those with GD had lower levels of the vitamin, and a higher risk of vitamin D deficiency.

Now, these results don't prove one causes the other, and experts are still unsure what to make of the connection. "It's not clear how the two could be linked," says chiropractic physician and nutritionist Gina Sirchio, DC, CNN, nutritionist, and author of The Nourish Series: Prenatal Nutrition. While you could ask your health care provider to measure the levels of 25-hydroxyvitamin D in your blood (your body converts this compound into active vitamin D), not all plans cover the test, and doctors don't agree on optimal levels in the first place.

But don't dismiss D: It's a vitamin worth adding into your diet regardless, especially considering that three-quarters of Americans are D deficient, according to another study. "The vitamin helps your baby's bones form properly, strengthens both of your immune systems, and may ward off postpartum depression," says Sirchio. Up your intake of fatty fish, like salmon and tuna (make sure you eat them cooked to avoid harmful bacteria), mushrooms, and fortified milk and juice.